As illustrated in FIGS. 1 and 2, an airplane comprises a skin 10 forming the fuselage, and an internal bulkhead 14 which delimits a flight deck 12.
In order to evacuate the pilots, the airplane comprises an escape opening 18 for bringing the inside of the flight desk 12 into communication with the outside 20 of the airplane, and at least one emergency door 22 for closing off or freeing the escape opening 18. According to an embodiment illustrated in FIG. 1, this emergency door 22 is positioned on the top part of the fuselage, vertically above the flight deck 12. This emergency door 22 comprises a wall with an external surface 24 flush with the external surface of the skin 10 of the fuselage. This emergency door 22 comprises a hinge 26 that allows it to pivot towards the inside of the flight deck, and locking/unlocking means 28 that are controlled by an internal opening controller 30 that is actuatable from the inside of the fuselage and by an external opening controller 32 that is actuatable from the outside of the fuselage. Inside the fuselage, the airplane comprises an emergency hatch 34 which closes off the escape opening 18 and ensures the continuity of the internal bulkhead 14 of the flight deck 12.
This emergency hatch 34 is in the form of a rigid panel which comprises:                on a first side, goosenecks 36 configured to allow the emergency hatch 34 to pivot into the open position and to come away from the internal bulkhead 14,        on a second side away from the first side, a locking/unlocking mechanism 38 configured to take up a locked state in which the mechanism 38 holds the emergency hatch 34 in the closed position, and an unlocked state in which it no longer holds the emergency hatch 34 in the closed position and allows it to pivot by virtue of the goosenecks 36,        on a face of the emergency hatch 34 that is oriented towards the inside of the flight deck, a first controller 40 configured to cause the locking/unlocking mechanism 38 to move from the unlocked state when it is actuated by a person from the inside of the flight deck,        on a face of the emergency hatch 34 that is oriented towards the emergency door 22, a second controller 42 configured to cause the locking/unlocking mechanism 38 to move from the unlocked state when it is actuated by the emergency door 22 while the latter opens.        
The first controller 40 is a handle connected to the locking/unlocking mechanism 38. The second controller 42 is a pivoting lever that is connected to the locking/unlocking mechanism 38 by way of a cable.
According to this configuration, the weight of the emergency hatch 34 favors the pivoting thereof towards the inside of the flight deck when it is no longer held by the locking/unlocking mechanism 38. Consequently, the emergency hatch 34 should have a certain mass in order to function correctly.